Long term access to a patient's bloodstream (longer than one month, for example) is required for many medical treatments including antibiotic therapy, hemodialysis access, chemotherapy regimens, and other treatments that require repeated infusion or blood processing. In some cases, internal access to the patient is required for years. Current devices and methods generally negatively impact the quality of the patient's life, and the patient sometimes develops complications as a result of the long term access. Vascular access devices used for longer term treatments include tunneled central catheters (including dialysis catheters), implanted infusion ports (including dialysis ports), dialysis grafts, and fistulas. A cuffed catheter can be used for non-vascular access, such as to the abdominal cavity for peritoneal dialysis to prevent infection.
Tunneled catheters can cause infection of the bloodstream or peritoneum and the skin entry site. The external portion of the catheter can fracture or otherwise fail due to its movement after placement. Also, the placed catheter can be accidentally or intentionally removed from the body, causing the patient pain and other complications. There is also the possibility of increased wear, damage, or disassembly caused by the patient “playing with” the placed device. The skin entry site requires constant maintenance and clamps are required to prevent bleeding through the catheter and to prevent air embolus. The portion of the catheter external to the patient's body frequently is uncomfortable for the patient. The external catheter and the skin entry site can prevent the patient from bathing normally or engaging in normal physical activities.
Subcutaneously implanted access ports require the use of needles to access the port through the patient's skin. Using needles, such as the large needles used for dialysis ports, creates the potential for infection and causes the patient pain. The access port reservoir has the potential of accumulating debris and harboring infection. In the event an internally-connected catheter connecting to this type of port needs to be replaced, a surgical procedure is required.
Grafts and fistulas on the patient's arm are disfiguring, and they require frequent access with large bore needles which causes pain and eventually destroys the access route. Grafts and fistulas also require invasive vascular surgery to be created and revised. Additionally, interluminal declotting is often necessary.
With respect to medical devices that are permanently implanted into a patient, such as a pacemaker for example, access is limited to surgical means in order to reach the device to replace batteries or repair components. Electrical leads that pass through the skin to supply power and control for the internally-implanted device can cause infection.